conjugated

adj.
  1. (Chem.) formed by the union of two compounds; as, a conjugated protein.
  2. joined together especially in a pair or pairs.
  3. (Chem.) containing two or more double bonds each separated from the other by a single bond; -- of an organic compound or of the double bonds thus arranged.

Conjugated double bonds have chemical and electronic properties different from those of isolated double bonds.